Conventional corrugating methods and machinery for making corrugated board employ a significant amount of heat energy in the form of steam at various stages of the corrugating process. For example, steam heat is used to heat the corrugating rollers to lower the coefficient of friction. This is so the medium that is drawn and formed into a corrugated web between those rolls is not unduly stressed or fractured due to friction-induced over-tensioning of the medium in the corrugating labyrinth.
A substantial amount of energy often also is used to preheat a face-sheet web prior to entering the single-facer or the double-backer. In each of these machines, a face-sheet web is adhered to one side of a corrugated web by contacting the face sheet with crests of respective corrugations (sometimes called “flutes”) located on one side of the corrugated web where a conventionally low-solids, high-water-content adhesive (typically 70-90% water) has been applied. The face sheets are preheated so they can more readily and uniformly absorb the high-water content adhesive on contacting the flute crests in order to form an adequate green-strength bond. These adhesives typically require additional heat to initiate a chemical change that creates the final bond. In some installations, the single-faced web (composed of a corrugated web with a first face-sheet web already adhered to one side) emerging from the single-facer also is preheated prior to entering the glue machine so the exposed flute crests will more readily absorb the high-water content adhesive, and so they will be closer to the temperature (commonly know as the gel point) that causes the chemical change to occur.
Lastly, a significant amount of heat energy is expended in the double-backer where hot plates conventionally are used to drive off excess moisture from the high-water content adhesive used to assemble the finished corrugated board. This heat cures the adhesive and provides a permanent bond.
A corrugating method that substantially reduces or eliminates the above-noted requirements for heat would significantly reduce the amount of energy expended in producing corrugated products. This would considerably lower the cost, and the associated waste, per unit of corrugated product produced.